238 Intelligence and Miscellaneous Articles, 



These observations give an increase of 1° centigrade in descend- 

 ing through 18*32 metres. 



Kupffer's observations in the mine of Bogoslowsk in the Ural, 

 give an increase of 1° centigrade in descending through 1984 

 metres. — Poggendorff 's Annalen, v. 32. 



ON THE PHYSICAL AND THERAPEUTIC PROPERTIES OF CHRO- 

 MATE OF POTASH. BY M. JACOBSON. 



Neutral chromate of potash may be exposed to a very high tem- 

 perature without being decomposed, unless charcoal be added to it, 

 which renders it incandescent. Hemp, cotton, linen, or cloth, im- 

 pregnated with this salt become very combustible, and burn with 

 strong and lively incandescence, and with considerable disengage- 

 ment of light and heat. The oxides of chromium and its different 

 salts possess the same property. The author has employed this 

 property of chromate of potash for the preparation of moxas. 

 Those which he made use of were made with blotting-paper soaked 

 in a solution made with one part of this salt and 16 parts of water: 

 the author proposes to make matches by immersing cotton in this 

 solution. An important property of this salt is its great solubility 

 in water, and its power of preserving vegetable and animal matter 

 from putrefaction ; it also removes the disagreeable smell from 

 putrid substances. 



The bichromate is especially suited for preservation and disinfec- 

 tion, the solution containing about 1*250 of its weight of the salt. 

 Animal substances, with the exception of the nervous parts, are 

 not at all altered by this solution. With respect to the therapeutic 

 properties of chromate of potash, M. Jacobson employs it externally 

 as a resolvent, and when concentrated, as a caustic. Internally, 

 taken in doses of 1 or 2 grains, it is emetic, — Journal de Chimie 

 Medicate, Fevrier 1834. 



DISCOVERY OF CHRENIC AND APOCHRENIC ACIDS IN THE MI- 

 NERAL WATERS OF PORTA. BY M. BERZELIUS. 



The waters of Porta have acquired great celebrity on account of 

 their medicinal properties. The water is abundant, and bubbles of 

 gas, which consist of 6 volumes of azote and 1 volume of carbonic 

 acid, constantly rise from the bottom of the spring : the temperature 

 of the water is invariably about 45° Fahr. The colour of the water 

 is yellowish, and caused by an organized substance which it is dif- 

 ficult to isolate; it is composed of oxygen, hydrogen, azote and 

 carbon. It possesses acid properties, and when concentrated has a 

 sour taste : it is a mixtureof two acids*, one of which, occurring in the 

 greatest quantity, Berzelius calls chrenic acid, and the other apochrenic 

 acid, because it is formed from the first by the influence of oxygen 

 gas, &c. These acids are weak ; they nevertheless decompose the 

 acetates if the mixture is evaporated. Chrenic acid does not 

 crystallize : the solution concentrated to the consistence of a syrup 

 is almost colourless. When dried in vacuo it splits in all directions, 

 and has a false appearance of being crystallized ; its taste is then 

 distinctly acid and astringent. The watery solution has only an 



